<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="js/jquery-1.8.3.js"></script>
</head>
<body>
    
    <p id="eat_id" class="eat_class">我能去你家吃饭吗？就一碗！！</p>
    <img src="ganfan.jpg" alt="img" width="300" height="300" id="ganfan_id">
    <br>
    <button id="ganfan_btn">来吧，干饭！</button>
    <script>
        $(document).ready(function(){
            $("#ganfan_btn").click(function(){
                // $("#eat_id").css("color","blue");
                // 通过id选择
                $("#eat_id").css({"color":"red","font-size":"30px"});
                // 通过class选择
                $(".eat_class").css("color","yellow");
                // 通过attribute 选择
                $("[src='ganfan.jpg']").css({"width":"400px","height":"400px"});
            });
        });

        
    </script>
    
</body>
</html>